1. Field of the Invention
This invention is related to clarifiers, and, in one aspect to a cover or roof for a clarifier vessel.
2 Description of Related Art
Clarifiers are used to separate suspended solids from a liquid in which they are suspended. A typical clarifier has a vessel for holding the liquid and, in some cases, a skimmer, or rake mechanism which facilitates movement of the solids upwardly so that a clear liquid remains. A wide variety of liquids are clarified, including liquids which emit gasses and vapors. Such emitted gasses and vapors are contained within the clarifier vessel.
A variety of problems result from the containment of such gasses and vapors and from their accumulation within a clarifier vessel. The gasses and vapors (e.g. hydrogen sulfide and vapors with entrained salt) can damage clarifier internal parts and corrode the metals used for them. Without appropriate pressure relief for covered clarifiers, an explosive situation is possible; but often such pressure relief must be accomplished in an environmentally acceptable manner. Prior art dome clarifier covers provide a relatively large space above material to be clarified. A large volume of dangerous, toxic, and/or potentially explosive gasses or vapors from the material can accumulate in this space.
There has long been a need for a clarifier and a clarifier roof which facilitate the effective venting of gasses and vapors from a clarifier vessel. There has long been a need for a clarifier roof which permits easy access to the clarifier's interior. There has long been a need for a clarifier roof that accommodates skimming equipment within the clarifier. There has long been a need for a clarifier with such apparatus. There has long been a need for a clarifier with minimal headspace.